GXSC analog-to-digital converter replaces AD7124 for pressure measurement application

With the rapid development of industrial intelligence, medical precision, and aerospace technology, the requirements for accuracy, integration, and reliability in pressure measurement continue to increase, and highly integrated simulation front-end has become the core driving force for system upgrades. The core process of a pressure measurement system is to convert pressure physical quantities into electrical signals through sensors. After analog front-end conditioning and analog-to-digital conversion, the back-end unit completes data processing and output.

The output signals of pressure sensors (such as piezoresistive and strain gauges) are mostly weak differential signals at the mV level, which are susceptible to temperature drift, power supply noise, power frequency interference, and environmental vibration. Moreover, the requirements for measurement accuracy, power consumption, and integration vary significantly in different scenarios. The 24 bit 16 channel highly integrated analog-to-digital converter of GXSC supports 50/60Hz simultaneous suppression by optimizing the ∑ - Δ modulator architecture. With 24 bit resolution, it can accurately detect signal changes at the microvolt level, which is essential for pressure measurement applications.

The GXSC analog-to-digital converter integrates multiple functions to reduce the system cost and component count of sensor measurement applications. This device features a low-noise, programmable gain amplifier, equipped with a single cycle steady-state digital filter and internal oscillator. The chip also provides a built-in low drift voltage reference and two matching programmable excitation current sources. The input multiplexer supports 8 differential inputs. In addition, the multiplexer integrates sensor burnout detection, thermocouple voltage bias, system monitoring, and universal digital I/O. PGA offers selectable gain up to 128V/V.

These features provide a complete front-end solution for pressure sensor measurement applications, including thermocouples, thermistors, resistance temperature detectors, and other small signal measurements, including resistance bridge sensors. Digital filters are stable within a single cycle to support fast channel switching when using input multiplexers and provide data rates of up to 19.2kSPS. For certain data rates, filters will suppress interference at 50Hz and 60Hz. Its main performance advantages are as follows:

• Effective resolution: 23bits

• Number of channels: 16 single ended/8 pairs of differential

• Output rate: up to 19.2kSPS

• High integration:

Integrated internal benchmark: temperature drift 8ppm/℃, 2.5V

› Programmable differential amplifier (integrated high impedance PGA): 0.02% initial accuracy

Integrate 2 channels with 0.1% matching degree IDAC

Integrated Bias voltage and wire breakage detection

Integrated 2 ℃ precision temperature sensor

• Supports 50/60Hz simultaneous suppression

Single cycle establishment and automatic channel scanning

• Support SPI CRC verification

Digital power supply: 2.7V~5.25V

• Analog power supply: unipolar (2.7V~5.25V)&bipolar (± 2.5V)

• Package: 5.00mm x 5.00mm QFN (32pin)

• Operating temperature range: -40 ° C to+125 ° C